very slight idle problem after replacing spark plugs

[3134]

I replaced my denso iridium spark plugs with ngk bpr7es spark plugs and gapped them .030 and after putting them in now my car idles rough, but it is barely noticable. It raises only at the most one notch between 0-1000 rpm. It sometimes goes away for 30 seconds then does it again. It will drop one little notch for 2 seconds then go up and down and the needle never stays steady. What is the problem????

 

[Whammydill]

It could just be your ECU making fine adjustments to your idle speed. However you can try gaping them down to .028 and see if that helps

 

[diablos991]

If it is the ECU setting itself then it should settle down after a couple hours or so of driving.
Also check to make sure that all your plug wires are on tight and making a nice tight solid connection. Check for corrosion as well.

 

[3134]

yea i checked the wires to make sure they were tight and the seemed tight, however i drove the car at most an hour and let it run at idle but i guess i need to drive it more before i rule out the ecu.

 

[Old Mitsu Tech]

Shouldn't make all that much difference. Is it only at idle? See if it studders when you snap the throttle. If it does, then possible you could have a spark plug boot which has lost integrity.

Let us know

 

[3134]

nope it doesnt studder, if anything when i accelerate it feel smoother and more responsive.

 

[16G AWD]

i had my motor rebuilt and they used champion spark plugs. could this be the reason i have a rough idle too??

 

[blownturbotsi]

Maybe a batch of bad gas?